The field of search-and-rescue diving is extremely dangerous, and many of the safety protocols take a significant amount of time, increasing the amount of time not only the diver but also the victim has to spend in the water. It also is difficult to see underwater below ice, due to a lack of sunlight, murky water, and due to the diver stirring up silt from the bottom of the body of water. Complicating matters in regions that suffer freezing winters, it is dangerous to stage search and rescue operations on frozen bodies of water because the ice may not be able to safely bear the weight of the diver's support team and equipment where the search takes place. Also, visibility is reduced in waters covered by ice, and dives are generally more difficult.